Message Bus

MessageBus

###################################################################
#  A Topic is a superclass that all Communications inherit from
#
#  A Communication Channel will accept a number of firms_topics it wants communications for.
#    eg.  A mobile Device will by default want to hear all communications.
#         If the device adds a filter they will not accept communications for
#         That type of message.
#
#    If it accepts a given firms_topic and there is a message to send.  The firms_topic
#    has one topic "belongs_to :topic" that performs the method `Process`.
#    The `process` method generally takes the params (device_id, object_id, message)
#
#  --------------                                --------------        ------------------
#  |  Firm      |                                | FirmsTopic |        |     Topic      |
#  |            |-------------------------------<|            |>-------|                |
#  |            |                                |            |        | medium         |
#  |            |                                |            |        | message_type   |
#  |            |                                |            |        | type           |
#  |            |                                |            |        | name           |
#  |            |                                |            |        | description    |
#  --------------                                --------------        ------------------
#        |                                             |
#        |                                             |
#       / \                                           / \
#  --------------        ------------------        ------------------
#  |  User      |        | Communication  |        |  Notification  |
#  |            |-------<| Channel        |-------<|  Filters       |
#  |            |        |                |        |                |
#  |            |        | type           |        |                |
#  |            |        | name           |        |                |
#  |            |        | meta           |        |                |
#  |            |        | options        |        |                |
#  |            |        | -------------  |        |                |
#  |            |        | medium (email) |        |                |
#  --------------        ------------------        ------------------
#
###################################################################

class Topic < ActiveRecord::Base
  #has_many :firms_topics # shouldn't be called as a method this would return all firm's firms_topics

  validates :description,   presence: true
  validates :name,          presence: true
  validates :medium,        presence: true
  validates :message_type,  presence: true, uniqueness: { scope: [:medium, :type]}

  MESSAGE_ADDED   = 'message_added'
  TASK_ASSIGNED   = 'task_assigned'
  TASK_COMPLETED  = 'task_completed'
  TASK_DUE_TODAY  = 'task_due_today'
  TASK_READY      = 'task_ready'
  INTEGRATION_INSTALLED = 'integration_installed'

  MESSAGE_TYPES   = [
    MESSAGE_ADDED,
    TASK_ASSIGNED,
    TASK_COMPLETED,
    TASK_DUE_TODAY,
    TASK_READY
  ]

  INFO = [
     { type: 'Topics::EmailMessageAdded',  medium: :email,  message_type: MESSAGE_ADDED,  name: 'Message Added',  description: 'Send notification to email when a message is added to a task that I follow.'},
     { type: 'Topics::EmailTaskCompleted', medium: :email,  message_type: TASK_COMPLETED, name: 'Task Completed', description: 'Send notification to email when a task is Completed that I follow'},

     { type: 'Topics::MobileMessageAdded', medium: :mobile, message_type: MESSAGE_ADDED,  name: 'Message Added',  description: 'Send notification to device when a message is added to a task that I follow.'},
     { type: 'Topics::MobileTaskCompleted',medium: :mobile, message_type: TASK_COMPLETED, name: 'Task Completed', description: 'Send notification to device when a task is Completed that I follow'},

     #{ type: 'Topics::SlackTaskAssigned',         medium: :slack, message_type: TASK_ASSIGNED, name: 'Task Assigned', description: 'Send personal notification to Slack when a task is assigned to me'},
     #{ type: 'Topics::SlackIntegrationInstalled', medium: :slack, message_type: INTEGRATION_INSTALLED,  name: 'Integration Installed', description: 'Send personal notification to Slack when Slack integration is installed'},
     #{ type: 'Topics::SlackMessageAdded',         medium: :slack, message_type: MESSAGE_ADDED,  name: 'Message Added',  description: 'Send notification to Slack when a message is added to a task that I follow.'},
  ]

  def perform(channel_id, object_id, message = nil, options = {})
    raise 'please implement `perform` in sub-class'
  end
end

####################################################################

class FirmsTopic < ActiveRecord::Base
  belongs_to :firm
  belongs_to :topic

  validates :topic_id, presence: true, uniqueness: { scope: :firm_id }
  validates :firm_id, presence: true

  delegate :description,
           :name,
           :medium,
           :message_type, to: :topic

  def deactivate!
    self.update_attributes(active: false)
  end
end

##########################################################

class CommunicationChannel < ActiveRecord::Base
  include Bitfields

  TYPES = ['MobileChannel', 'EmailChannel', 'SlackChannel']

  belongs_to  :user

  has_many    :notification_filters
  has_many    :filtered_firms_topics, -> { where(firms_topics: { active: true }) },
                                through: :notification_filters,
                                class_name: 'FirmsTopic', source: :firms_topic

  scope :active, -> { where(active: true) }

  validates :name,    presence: true, uniqueness: {scope: :user_id}
  validates :user_id, presence: true

  bitfield :options,  1 => :allows_daily_digest

  # meta data about the device (for things like OS/model/???? )
  serialize :meta, Hash

  delegate :firm, to: :user, allow_nil: false

  attr_accessor :email, :device_token, :endpoint_arn

  def deactivate!
    self.update_attribute(:active, false)
  end

  def activate!
    self.update_attribute(:active, true)
  end

  # 1) if the device(communication_channel) is marked inactive then it will not get ANY notification firms_topics
  # 2) if the firm shut off the notifications the device(communication_channel) will not get the notification firms_topic
  # 3) otherwise grab all firms_topics that the user has not filtered that are available for the firm
  def allowed_firms_topics
    if active
      firm.firms_topics.includes(:topic).where(topics: {medium: medium}).where.not({firms_topics: {id: notification_filters.pluck(:firms_topic_id) }})
    else
      []
    end
  end

  def allows_firms_topic?(topic_id)
    if active
      allowed_firms_topics.where(topics: {id: topic_id}).exists?
    else
      false
    end
  end

  def firms_topics_for(message_type)
    if active
      firm.firms_topics.includes(:topic).where(topics: { medium: medium, message_type: message_type }).where.not({firms_topics: {id: notification_filters.pluck(:firms_topic_id) }})
    else
      FirmsTopic.none
    end
  end

  def add_to_message_bus(message_type, object_id, message = nil, options = {})
    firms_topics_for(message_type).map { |firm_topic| firm_topic.topic.perform(id, object_id, message, options) }
  end

  def medium
    # sub-class should implement this method
    raise NotImplementedError.new("Add `medium` method to #{self.class}")
  end

  def identifier
    #
  end

  def identifier_name=(val)
    # do nothing
  end

end

###############################################

class NotificationFilter < ActiveRecord::Base
  belongs_to :communication_channel  # null false in DB
  belongs_to :firms_topic                  # null false in DB

  delegate :topic_id,
           :description,
           :name,
           :medium,
           :message_type, to: :firms_topic
end

################################################

class Firm < ActiveRecord::Base
  has_many :firms_topics, -> { where({firms_topics: {active: true }}) }
  has_many :all_firms_topics, class_name: 'FirmsTopic'
  after_commit :assign_all_firms_topics, on: :create


  private

  def assign_all_firms_topics
    Topic.all.each do |trigger|
      self.firms_topics.where(topic_id: trigger.id).first_or_create(active: true)
    end
  end
end

################################################

class User < ActiveRecord::Base
  
  has_many :communication_channels
  has_many :email_channels
  has_many :mobile_channels
  has_many :notification_filters, through: :communication_channels
  has_many :slack_channels, source: :communication_channels, class_name: 'SlackChannel'
  
  
  # @user.add_to_message_bus
  #
  # This method does all the heavy lifting for sending messages/information to
  # users.
  #
  # The message bus is NOT responsible for knowing if the user was suppose to
  #   receive the message to begin with.  If you put a message on the bus and the
  #   user has any type of communication turned on, they WILL receive the message.
  #   HENCE, the message bus does not check permissions, it just sends messages to all
  #   communication channels turned on for a given message_type.
  #
  #  NOTE: you can look at the processing of the messages in models/triggers/* { :method_name => 'process' }
  def add_to_message_bus(message_type, object_id, message = nil, options = {})
    raise "#{message_type} must be a recognized message type: #{Topic::MESSAGE_TYPES}" if !Topic::MESSAGE_TYPES.include?(message_type.to_s)
    channels = communication_channels.where(active: true)
    channels.each do |channel|
      channel.add_to_message_bus(message_type, object_id, message, options)
    end
  end
end

################################################

class EmailChannel < CommunicationChannel
  validate :email_present

  def email
    self.meta['email']
  end

  def email=(value)
    self.meta['email'] = value
  end

  def medium
    'email'
  end

  def identifier
    email
  end

  def identifier=(val)
    self.email=(val)
  end

  def identifier_name
    'email'
  end

  def email_present
    if meta['email'].blank? || !meta['email'].match(Devise.email_regexp)
      self.errors.add(:base, 'This is not a valid email')
    end
    true
  end
end

############################################

# endpoint_arn
#   - an endpoint token for a device or mobile app on one of the supported push notification services, such as GCM and APNS
#
# device_token
#   - REFERENCE:  http://www.jamesransom.net/?p=27
#   - To obtain your device token for testing on chrome refer to the README at
#     * https://github.com/scalus/sample_push_notification

class MobileChannel < CommunicationChannel
  include ActionView::Helpers::NumberHelper

  validates :endpoint_arn, :device_token, presence: true, if: :active?

  before_validation :obtain_endpoint_arn

  def medium
    'mobile'
  end

  def identifier=(val)
    self.device_token=(val)
  end

  def identifier_name
    'mobile'
  end

  def identifier_name=(val)
    #
  end

  def endpoint_arn=(endpoint_arn)
    self.meta[:endpoint_arn] = endpoint_arn
  end

  def endpoint_arn
    self.meta[:endpoint_arn]
  end

  def device_token=(device_token)
    @device_token_changed = (self.meta[:device_token] != device_token)
    self.meta[:device_token] = device_token
  end

  def device_token
    self.meta[:device_token]
  end

  def is_sandbox
    self.meta[:is_sandbox]
  end

  def is_sandbox=(flag)
    self.meta[:is_sandbox] = !!flag
  end

  def obtain_endpoint_arn!
    obtain_endpoint_arn
    self.save
  end

  def sns_client
    @sns ||= Aws::SNS::Client.new
  end

  def publish(hash)
    sns_message = {
        default: hash.delete(:default),
        APNS_SANDBOX: { aps: hash.to_json },
        APNS: { aps: hash.to_json }
    }
    sns_client.publish(target_arn: self.endpoint_arn, message: sns_message.to_json, message_structure: 'json')
  end

  private

  def obtain_endpoint_arn
    platform_arn = self.is_sandbox ? Settings.aws.sns.ios.application_arn : Settings.aws.sns.ios.sandbox_arn

    if device_token.present? && (endpoint_arn.blank? || @device_token_changed)
      endpoint = sns_client.create_platform_endpoint(
          platform_application_arn: platform_arn,
          token: device_token
      )
      self.endpoint_arn = endpoint[:endpoint_arn]
    end
    true
  end

end

#######################################
class EmailTopic < Topic

end
#######################################
class Topics::EmailMessageAdded < EmailTopic

  def perform(channel_id, comment_id, message, options)
    # send device the message with a push notification
    channel            = CommunicationChannel.includes(:user).find(channel_id)
    user_id_to_message = channel.user_id
    comment_id         = comment_id # Comment.includes(:task).find(comment_id)

    # options optionally have recipient_names
    options = ActiveSupport::HashWithIndifferentAccess.new(options)
    options.reverse_merge({recipient_names: []}) # default to no options

    send_message(channel.user_id, comment_id, options[:recipient_names])
  end

  private

  def send_message(user_id, comment_id, recipient_names)
    TaskMailer.delay.new_comment_notification(user_id, comment_id, recipient_names: recipient_names)
  end
end
#######################################
class Topics::EmailTaskCompleted < EmailTopic

  def perform(channel_id, task_id, message, options) # updater_id is a required option
    # send device the message with a push notification
    channel  = CommunicationChannel.includes(:user).find(channel_id)
    task     = Task.find(task_id)

    options            = ActiveSupport::HashWithIndifferentAccess.new(options)
    options.reverse_merge({updater_id: nil})
    options.reverse_merge({recipient_names: []})
    options.reverse_merge({new_comment: false})

    send_message(channel.user_id, task.id, options[:updater_id], options[:new_comment], options[:recipient_names])
  end

  private
  def send_message(user_id, task_id, updater_id, new_comment, recipient_names)
    TaskMailer.delay.resolved_notification(user_id,
                                           task_id,
                                           updater_id,
                                           new_comment: new_comment,
                                           recipient_names: recipient_names)

  end
end
###################################
class MobileTopic < Topic

  def sns
    Aws::SNS::Client.new
  end
end
###################################
class Topics::MobileMessageAdded < MobileTopic

  def perform(channel_id, comment_id, message, options)
    # send device the message with a push notification
    @channel = MobileChannel.includes(:user).find(channel_id)
    @comment = Comment.find(comment_id)

    send_message
  end

  private

  def send_message
    sns = Aws::SNS::Client.new
    title = truncate("New Message: #{@comment.commentable.title}", length: 40, omission: '...')
    message = { default: title, sound: 'default', badge: 1, alert: title }
    sns.publish(target_arn: @channel.endpoint_arn, message: message, message_structure: 'json', subject: 'test')
  end
end
###################################
class Topics::MobileTaskCompleted < MobileTopic

  def perform(channel_id, task_id, message, options)
    # send device the message with a push notification
    @channel = MobileChannel.find(channel_id)
    @task    = Task.find(task_id)
    send_message
  end

  private

  def send_message
    title = truncate("Completed: #{@task.title}", length: 40, omission: '...')
    message = { default: title, sound: 'default', badge: 1, alert: title }
    @channel.publish(message)
  end
end

###################################
require 'slack'

class SlackTopic < Topic
  include Rails.application.routes.url_helpers
  include ActionView::Helpers::TextHelper
  include ApplicationHelper

  private

  def slack
    Slack.configure do |config|
      config.token = token.token
    end
    Slack
  end

  def token
    @token ||= IntegrationToken.where(application: Integrations::SlackService::APPLICATION, firm_id: @firm.id).last
  end
end

###################################
class Topics::SlackTask < SlackTopic

  def task_list_text
    if @task.project
      "\n*Tasklist*\n #{@task.project.title.html_safe}"
    end
  end

  def task_url
    riveter_tasks_url(host: @firm.main_host) + '/' + @task.id.to_s
  end

  def task_actions
    links = []
    links << "<#{ complete_task_with_token_url(@task, @user, { host: @firm.main_host })  }|Complete Task>" if @user.present? && @task.can_be_email_completed_by?(@user)
    links << "<#{ unfollow_task_with_token_url(@follower, { host: @firm.main_host }) }|Unfollow Task>" if @follower.present? && !@follower.required_follower?
    links.join(' • ')
  end

  def for_company_text
    @task && @task.company ? "for #{@task.company.name.html_safe}" : ''
  end
end
###################################
module Topics
  class SlackMessageAdded < SlackTask

    def perform(channel_id, comment_id, message = nil, options = {})
      # send device the message with a push notification
      @channel = CommunicationChannel.includes(:user).find(channel_id)
      @comment = Comment.find(comment_id)
      @task = @comment.task
      @author = User.find_by_id(@comment.created_by)
      @firm = @task.firm
      @follower = @task.task_followers.where(follower_id: @channel.user_id).first
      send_message
    end

    private

    def send_message
      response = slack.post('chat.postMessage', channel: @channel.slack_user_id, token: token.token,
                            username: 'Scalus Notifications',
                            icon_url: Settings.slack.bot_logo_url,
                            attachments: [{
                                              pretext: pretext,
                                              fallback: pretext + ' ' + task_url,
                                              color: '#EEE',
                                              title: @task.title.html_safe,
                                              text: text,
                                              title_link: task_url,
                                              mrkdwn_in: ['text']
                                          }].to_json
      )

      response['ok']
    end

    def pretext
      @author ? "#{@author.name_or_email} added a new message to this task" : 'A new message was added to this task'
    end

    def text
      [
          truncate(@comment.try(:body).to_s.html_safe, length: 50),
          task_url,
          task_actions,
          task_list_text
      ].join("\n")
    end
  end
end

###################################

###################################